The EC300E, which is now entering field testing, generates 'free' energy via a boom-down motion which charges energy-storing accumulators that are used to power the hydraulic pump.
Volvo CE says the EC300E is unlike other systems that capture the swing energy of an excavator's superstructure to electrically assist the engine. Its hydraulic hybrid harvests 'free' energy generated by the down motion of the excavator's boom and uses it to supercharge the hydraulic system.
"The powerful and regular boom-down motions charge 20 litre hydraulic accumulators, which then deliver energy to drive hydraulic assist motors that help power the hydraulic pump," the company states. "There are the same levels of controllability and performance as the standard EC300E, including the ability to work in ECO mode and Hybrid mode simultaneously."
Volvo CE says this process takes load off the engine, and in the process delivers between 10-12% lower fuel consumption, up to 12% less CO2 emissions, and with no loss of performance.
The company adds that, when used in production 'dig and dump' applications (especially those with a 90o swing), the payback of this approach can be a little more than a year. The machine is claimed to provide the same levels of controllability and performance as an equivalent conventional machine, and up to 17% fuel efficiency improvement dependent on application.
While not commercially available yet, EC300E Hybrids are currently undergoing tests at customer sites in order to validate the technology in real world applications.
